Electric stapler



Oct 11, 1956 YAsUZo HATAZAKI 3,278,101

ELECTRIC STAPLER Filed Feb. lO, 1964 4 Sheets-Sheet 1 F/g/ F/g. 3

ATTORNEYS Oct. 11, 1966 YAsUzo HATAZAKI 3,278,101

ELECTRI C STAPLER Filed Feb. lO, 1964 4 Sheets-Sheet 5 94m F/g. 6 55/6/0/ 5 u 2Q ATTORNEKS Oct. 11, 1966 YAsuzo HATAzAKl ELECTRIC STAPLER 4Sheets-Sheet 4 Filed Feb. l0, 1964 ATTORNEYS United States Patent G3,278,101 ELECTRIC STAFLER Yasuzo Hatazalri, (Esedra, liapan, assignerto Matsushita Electric industrial Co., Ltd., Usaka, Espan, a corporationof .l'apan Fiied Feb. 10, 1%4, Ser. No. 343,863 Claims priority,application tapan, Feb. 14, 1963, 38/ 9,935, .1S/9,939; Apr. 15, 1963,Tait/28,1136, lig/28,041; May 10, 1963, Sti/35,108, Sii/35,113,EHS/35,117; May 16, 1953, SiS/36,734; Dec. 28, 1963, C19/24 2 Ciairns.(Ci. 227-7) This invention relates to ian electric stapler apparatusutilizing electromagnetic force for actuating it in which anelectromagnet is magnetized automatically by insertion of sheets ofpaper to drive a staple into the sheets in order to fasten themtogether.

A principal featureof the present invention consists in that a relay isactuated, instantaneously by the charging current of a capacitor,thereby energizing an electromagnet instantaneously to produce animpulse of electromagnetic force in the electromagnet to drive a staple.

Another feature of the present invention allows for force control inthat said capacitor is either variable in capacitance or intermediatecircuit taps may be provided on the coil of the electromagnet over whichelectrical connection may be changed to adjust the electromagnetic forceproduced in the electronragnet to drive the staple with proper impulseforce depending upon load on the staple, as, for example, thickness ofthe sheets .to be fastened or number of the sheets.

Still another feature of the present invention is to provide convenientmeans fior detecting presence of staples within a staple reservoir andindicating means visible from the exterior of the device.

Still another feature of the present invention consists in the provisionof a switch which engages the sheets of paper to actuate 1anelectromagnet when the sheets are inserted and which switch may beadjusted in its position to adjust the fastening position of the sheets.

Further features of the present invention include: an armature of theelectromagnet which is adapted to move horizontally to suppressvibration; the whole apparatus being of a reduced size; resupply ofstaples being facilitated by providing a push button for making a slidecase disposed within the staple reservoir readily extractable, thearmature of the electromagnet being operatively connected to the staplemagazine and a striking member for `driving a staple by means of a leverand other parts being so arranged iand adjusted as to reduce the size ofthe apparatus exceedingly.

The present invention will be now described in detail in conjunctionwith the accompanying drawings in which:

FIG. 1 shows a schematic front elevation of an electric staplerapparatus embodying the present invention;

FIG. 2 shows a schematic side elevation of the apparatus shown in FIG.l;

FIG. 3 shows a detailed ifront elevation of the apparatus shown in FIG.1, the casing thereof being removed .to show the internal mechanism;

FIG. 4 shows a top plan view of the apparatus shown in FIG. l in detail,the casing thereof being also removed;

FIG. 5 is a side elevation in cross section of the apparatus shown inFIG. l, taken along a line A-A in FIG. 4;

FIG. 6 is ia rear view in cross section of the apparatus shown in FIG. ltaken along a line B-B in FIG. 4;

FIG. 7 shows a fragmentary side elevation in cross section of theapparatus shown in FIG. 1 taken along a line C-C in FIG. 4;

FIG. 8 shows an exploded perspective view of principal ICC parts `of theinternal mechanism of the apparatus shown in FIG. l; and

FIG. 9 shows an electrical wiring diagram tof the apparatus shown inFIG. l.

Referring to the drawings, particularly to FIGS. 1 to 5, a casing 2 madeof synthetic resin is secured to a diecast base member 1 by means otbolts 3. Between the front part of the base member 1 and the casing 2there is provided a gap ttthrough which sheets of paper to be fastenedtogether are inserted. The gap 4i presents the bottom Xof a staplemagazine 5 containing staples. A staple clincliing anvil 6 is mounted onthe base member 1. A lever S for a microswitch '7 for actuating thestapler apparatus protrudes through the gap 4 and a groove 9 for guidingthe lever 8 is formed in the base member 1.

in operation, when sheets of paper to be fastened are inserted betweenthe staple anvil 6 and the staple mag-azine 5, the lever 8 is depressedby the sheets and an electromagnet is magnetized by the making of theoontacts of the microswitch 7. At this moment, electromagnetic force ofthe electromagnet forces the staple magazine to move sharply against thestaple anvil 6 while one of the staples contained in the staple magazine5 is driven into the sheets by the driver. Thus the sheets are fastenedtogether. In order to replenish the staple magazine with staples, asliding case in the staple magazine 5 is adapted to be withdrawn bypushing a button 11 which projects `from the side of the base member 1.The sliding case may be inserted into and fixed within the staplemagazine 5 by pushing the sliding case at its front face 61. Over theside of the base member 1 protrudes a knob 12 for adjusting thefastening position of the sheets. The rnicroswitch 7 and the lever 8 aremoved in the direction shown by an arrow D by rotation of the knob 12and thus the position of contact point between the sheet and the lever'8 is changed in respect to the staple `anvil 6 so that the fasteningposition in the sheets may be adjusted. A transparent body 13 is mountedin front of the casing 2 and an indicating lamp 14 is arranged insidethe casing near the transparent body 13. This indicating lamp 14provides a means for indicating the presence of staples within thestaple magazine 5. Thus when there are some staples in the staplemagazine 5, the indicating lamp 14 is lighted thereby illuminating thetransparent body 13. Rubber suction cup feet are mounted on the bottomof the base member 1.

Next the internal mechanism of the apparatus will be described inreference to FIGS. l to 8. The `upper rear portion P of the base member1 is formed in an open dishlike shape. A xture 16 is secured to the basemember, within this portion, by means of screws 17. An electromagnet 19is secured to the fixture 16 at its upper face 18 by means of screws211. The electromagnet 19 comprises an iron core 21, a magnetizing coil22 and an armature 23. When the magnetizing coil 22 is energized, thearmature 23 is attracted so that the end 24 of the armature 23 willproject from the core 21. The staple magazine 5 is supported in seesawmanner on a support 25 which is secured within the fixture 16 on thebase member 1 by means of screws 26 which pass through holes 126. Ashaft 29 is mounted through holes 27 in the support member 25 and inalignment with holes 23 in the staple magazine 5. The staple magazine istherefore pivoted about the shaft 29. The staple magazine 5 is formed asan L-shaped member and is provided with a slot 39 in its front wall,locking holes 31 in its bottom wall and a hole 33 in its side wall 32,as shown in FIG. 8. A leaf spring 35 having a paw 34 is secured to theside wall 32 at a point Q, with the paw 34 projecting through the hole33. A cover 37 having substantially V-shaped cross section and beingformed with a guide groove 36 ta along the axis thereof is fitted on thetop of the staple magazine 5. Tabs 38 of the cover 37 are inserted intothe locking holes 31 and bent to fix the cover 37 to the magazine 5. Astaple follower 39 is slidably mounted inside the cover 37 and a `guidepiece 40, which is formed of a portion of the staple follower, protrudesslidably through said guide groove 36. A slide plate 43 is provided witha hole 41 and a projection 42 and slides on the upper surface of cover37 to which it contacts. Namely, the slide plate 43 is mounted on thetop of the cover 37, with a guide 44 thereof extending through the guidegroove 36 to the back side of the top surface of the cover 37 from abovesaid top surface. A portion 45 at the end of the guide 44 is flexed onthe backside and in parallel to the top surface of the cover 37. Theaforementioned guide piece 40 projecting from the guide groove 36engages the hole 41 in the slide plate 43. This engagement of the guidepiece 40 with the hole 41 combines the slide plate 43 with the staplefollower 49 integrally and the top surface of the cover 37 is placedbetween the slide plate 43 and the staple follower 49. A guide 44 of theslide plate 43 is tted into the guide groove 36 and a portion 45 of theguide 44 is folded toward inside the cover 37. Thus the staple follower39 and the slide plate 43 are guided by the guide groove 36 and slide asa unit.

A sliding case 46 having an inner case 48 is inserted into the staplemagazine through an opening 47 in the front wall of the magazine 5. Thelegs 52 of staples 51 and side wall 53 of the staple follower 39 aretted slidably into gaps formed between the side walls of the slidingcase 46 and the inner case 48. Thus the front end 54 of the staplefollower 39 is adapted to engage with the adjacent end of the group ofthe staples 51. In this connection, the rear end 58 of a pin 57 whichextends through a hole 56 formed in the rear wall 55 of the staplefollower is fixed to the rear end of the staple magazine 5. A spring 60,which surrounds the pin 57, is interposed between the rear end 59 andthe rear wall 55 of the staple follower 39 to urge constantly the staplefollower 39 toward the front wall 61 of the sliding case 46. The sidewall 50 is provided with a notch 62 with which the paw 34 of the leafspring 35 engages. When the paw 34 is disengaged from the notch 62, thesliding case 46 is forced to move outwardly through the front opening 47of the staple magazine 5 as the front wall of the sliding case 46 isdriven by the front end 54 of the staple follower 39 which is urged bythe spring 60. For the purpose of releasing the paw 34 of the spring 35from the notch 62 of the sliding case 46, a pin 63 which is adapted toengage the end of the spring 35 is supported in two lugs 64 and 65formed in the base member 1. A stopper 66, mounted on the pin 63, isarranged between said two lugs 64 and 65, and a spring 67 which isadapted to urge constantly the pushbutton 11 on the pin 63 outward ofthe base member 1. When the push button 11 is depressed, the pin 63 isdisplaced axially and the end of the pin 63 forces the spring 35 todisengage the paw 34 to the spring 35 from the notch 62 in the slidingcase 46. A guide plate 69 encloses the front wall 68 of the staplemagazine 5 and is spaced slightly therefrom. The guide plate is mountedby means of screws 71 and is provided with a slot 70 arranged inalignment with the slot in the front wall 68 of the staple magazine 5. Astaple driver 72 having a connecting hole 73 is slidably fitted in thegap formed by the front wall 68 of the staple magazine 5 and the guideplate 69. The bottom face of the staple driver 72 moves inside of thefront wall 61 of the sliding case 46 and strikes the top of one of thestaples 51 contained within the sliding case 46 to drive the staple fromthe bottom of the staple magazine 5 toward the staple anvil 6. Amicroswitch 74 is provided for lighting the lamp 14 for indicating thepresence of staples 51 within the sliding case 46. This microswitch 74is mounted on the side wall of the staple magazine 5 with its button 75adapted to effect switching action by engaging with the projection 42upon sliding movement of the slide plate 43. Thus, if any staples arecontained within the sliding case 46, the projection 42 of the slideplate 43 does not contact with the button 75 of the microswitch 74 sincethe front end 54 of the staple follower 39 contacts with the end of thestick of staples 51 and the staple follower 39 and the slide plate 43are located in the middle of the staple magazine 5. This microswitch '74is mounted on the side surface at the forward end of the staple magazine5. On the other hand, the slide plate 43 is guided by the guide groove36 together with the staple follower 39 and slides on the top surface ofthe cover 37 which is mounted on the magazine 5. When the slide plate 43is positioned at the forward end of the top surface of the cover, theprojection 42 of the slide plate 43 cornes into contact with the button75 of the microswitch 74 and brings the microswitch 74 into the openstate, whereas the slide plate 43 is not positioned at the forward endof the top surface of the cover 37 (i.e., when the slide plate 43 ispositioned to the rear of the microswitch 74), the rffjection 42 doesnot corne into Contact with the button 75 of the microswitch 74, thuskeeping the microswitch 74 in the closed position. This position of theslide plate on the top surface of the cover 37 is variable by the numberof staples contained in the slide case 46. In other words, upon chargingthe staples 51 in the slide case 46 and then placing the slide case 46in the staple magazine 5, one end the staples 51 contacts the front wall61 of the slide case 46, while the other end thereof contacts the frontend 53 and 54 of the staple follower 39 and, in that position, thestaples 51 are pressed by the front end 53 and 54 against the front wall61 of the slide case 46 by the force of spring 6i). Therefore, when nostaples remain in the slide case 46, the staple follower 39 ispositioned at the forward end of the staple magazine 5 with its frontend 53 and 54 being in contact with the front wall 61 of the slide case46 and the slide plate 43, connected to the staple follower 39, beingpositioned at the forward end at the top surface of the cover 37. On thecontrary, when staples are present in the slide case 46, the staplefollower 39 and the slide plate 43 are located rearwardly at a distancecorresponding to the length of the staples, with the projection 42 onthe slide plate 43 being located rearwardly of the button 75 of themicroswitch 74 without depressing said button 75, i.e., the microswitch74 is held in a closed position lighting the indicating lamp 14. Whenthe staples within the sliding case 46 have been used up, the staplefollower 39 and the slide plate 43 are forced to move forward by theaction of the spring 60 and the projection 42 of the slide plate 43depresses the button '75 of the microswitch 74 to open it. As a result,the indicating lamp is extinguished.

A pin 78 is extended through the hole 77 in the middle portion of a bellcrank 76 with the both ends thereof being supported in bores S2 formedin ears 81 of the staple magazine 5 through spacers 79 and 3@respectively. The bell crank 76 serves to transmit the movement of thearmature 23 of the electromagnet 19 to the staple driver '72 and also totransmit the movement of the armature 23 to the staple magazine 5. Thusthe bell crank '76 is pivoted about the pin 73. One end 83 of the bellcrank 76 extends through the slot 70 to iit into a connecting hole 73 inthe staple driver 72 and the other end of the bell crank 76 has a holeS4 through which a pin 85 extends. The ends of the pin 85 are supportedby the end 24 of the armature 23 of the electromagnet 19 through theintermediary of spacers 86 and 37. In this connection, a resilient pad8S is applied to the core 21 in order to obtain shock absorbing effectbetween the magnetic core 21 and the bell crank 76. A spring 89 ismounted between the bell crank 76 and the staple magazine 5 about thepin 78 and serves to urge constantly the armature 23 and the bell crank76 in the directions shown by S and R', respectively. A spring 92 whichis tensioned between a lug 90, formed by bending a portion of the top 18of the fixture block 16, and a hole 91 in the ear 81 of the staplemagazine forces the front opening 47 of the staple magazine 5 upward. Alever guiding plate 93 is secured to the upper surface 18 of the fixture16 and has a tab 93. Since the side of the bell crank 76 pivots incontact with the tab 93 of the lever guiding plate 93 when the lever ispivoted about the pin 78 as a result of movement of the armature 23 ofthe electromagnet, an irregular swing in the direction along the axis ofthe pin 78 or 85 in the course of pivoting movement of the bell crank 76is avoided. Accordingly, the motion of the armature 23 of theelectromagnet can be transmitted to the staple driver 72 in a precisemanner. Namely, play is provided between the ends 24 of the armature 23and the core 21 so as to facilitate the movement of the armature 23, theends 24 are movable somewhat axially of the pin 85. Similarly, in orderto ease the movement of the bell crank 76, play is provided between thehole 84 and the pin 85, between the center hole in the spacer 87 and thepin 85 between the spacer 86 and the bell crank 76, between the spacer87 and bell crank 76, between the end 24 of the armature 23 and thespacer 86, between the end 24 of the armature 23 and the spacer 87,between the hole 77 and the -pin 78, between the center hole in thespacer 79 and the pin 78, between the center hole in the spacer 80 andthe pin 78, between the spacer 79 and the bell crank 76, between thespacer 80 and the bell crank 76, between the ears 81 of the staplemagazine 5 and the spacer 79, and between the ears 81 of the staplemagazine 5 and the spacer 80, wherefore the bell crank 76 is alsodisplaceable axially of the pins '78 and 85. If the lever guiding plate93 is not present here, the bell crank 76 swings irregularly in alateral direction axially `of the pins 78 and 85 along with the movementof the armature 23 and, as a result, the motion of the armature 23cannot be transmitted to the staple driver 72 with accuracy. Againstthis, in the embodiment shown in the figures, there is provided thelever guiding plate 93 having a tab 93' and the spring 89 urges thearmature 23 as well as the bell crank 76 in the direction shown byarrows S' and R respectively and simultaneously keeps the bell crank 76always in pressure contact with the tabs 93 of the lever guiding plate93. Such being the arrangement, the side surface of the bell crank 76rotates in contact with the tab 93 of the lever guiding plate 93 as thebell crank 76 rotates about the pin 78, the bell crank makes no lateralmovement in the axial direction of the pin 79 or 8S. Consequently, themotion of the armature 23 can be transmitted to the staple driver 72with high accuracy.

The microswitch 7 for actuating the stapler apparatus is mounted on thehead of a 'guide plate 94 which has formed in its side a cut bent lug 95which is slidably fitted into a slot `96 formed in the side wall of thefixture 16. The guide plate 94 is mounted Ion the side wall of thefixture 16 by means of a screw 97 and a nut 98 so that the `guide platemay slide `horizontally with the iug 95 being fitted into the slot 96las described above. Thus `the screw 97 extends through the slot 96 withthe head youtwardly projecting from the side surface of the fixture 16and further the shaft `101 is inserted in a spring 104 with fthe Iknob12 fixed to the tip end thereof. In the adjusting shaft l101, there isformed a cutaway portion 105, while the disc 103 is formed at its centerwith a partiaily flattened surface or circular center hole 106 throughwhich the cutaway portion extends. By the engagement of the cutawayportion =105 on the shaft 101 with the center hole 106, the disc 103 isprevented from rotating with respect #to the shaft 101 and rotatesintegrally with [the shaft 101 as the latter rotates. The knob 12 has onits peripheral surface a set screw 12a which is screwed in said knob inthe direction perpendicular to the axis of the shaft 101. After the knob12 is mounted to the end extremity of the shaft 101, the set screw 12ais tightened by screwing against Athe cutaway portion 105 of the shaft101 to thereby -x the knob 12 to the end of the shaft l101 so that theknob 12 rotates integrally with the shaft 101. ABetween the knob 12 andthe disc 10'3 is mounted a spring 104, by the force of whichthe disc 103is pressed against the side surface of `the fixture 16. Since the gearWheel 100 meshes with the rack 99, when `the -knob y12 is rotated, thegear wheel 100 is rotated and, as a result, the microswitch mounted onthe guide plate 94, which is engaged with said gear 100, moveshorizontally in the direction shown by arrow D. Moreover, the side wallof the fixture 16 is provided with a plurality -of proje-ctions 108which are adapted to lit into a plurality `of recesses 107 in theretaining disc 103. As the adjusting shaft is turned, the projections108 are snap-fitted finto the succeeding recesses 107 so that theangular position of the shaft 101 is prevented from slipping ou-t of anyone of predetermined positions under `the influence of vibration.

An electromagnetic relay 121 is secured to the rear portion of .the basemember 1 by means of screws 109 and an electric insulator b-oard 110 ismounted on the side yof the electromagnetic relay 121. A resistor 111and a diode clamp 112 are disposed on the insulator board 110. They arecovered by insulating resin to fix them in place. An electric insulatorboard 114 is secured by a screw 115 Ito an ear 113 formed in the rearend of the fixture 16. `O11 the insulator board 114 there are disposed acapacitor 116, a rectifier 117 and resistors 118 and 119 and they arecovered by insulating resin to fix them in place.

Next the electrical circuit for the electric stapler apparatus will beexplained in reference to FIG. 9. The magnetizing coil 22 of theelectromagnet 19 is connected across terminals W and W of a power sourcethrough a contact 120 of the electromagnetic relay 121. A coil 122 ofthe electromagnetic relay 121 is connected across the terminals W and Wthrough the capacitor 116, the rectifier 117, the microswitch 74 and theresistor 118 when fthe switch contact `of switch 7 contacts thestationary contact m. Further, the resistors 111 and 118, the indicatinglamp 14 and rthe microswitch 74 are connec-ted in series across theterminals W and W of the power source and fthe resistor 119 is connectedacross the electrodes of the capacitor 116 i-n series with the contact nof the microswitch 74. The diode clamp 112 is connected across the coil122 of the electromagnetic relay 121 Ito suppress transient high voltagewhich might be produced across the coil 122 and hence sparking dischargeacross the contact of microswitch 74.

When there are some staples within the staple magazine 5 the contact ofthe microswi'tch 74 is closed, the indicating lamp 14 is lighted and thecontact of the change lover microswitch 7 is closed on the pole n. Butupon `insertion yof the sheets of paper to be fastened into fthe Afrontpart of the stapler apparatus the lever of the change over microswitch 7is urged by the sheets to contact against the pole m. As a result,charging current flows to the capacitor 116 through the resistor 118 andthe rectifier 117 and through the coil 122 of the electromagnetic relay121 to magnetize it and thus fthe contact 120 is closed therebymagnetizing the coil 22 of the electromagnet so that one of the stapleswithin the staple magazine 5 is driven into the sheets lof paper bymeans of the previously mentioned linkage comprising the armature 23,the `lever 76, the staple magazine 5 and the staple driver 72. Sincefthe charging current of the capacitor 116 effects magnetization of thecoil 122 of the electromagnetic 'relay 121, lthe coil 122 is magnet-izedinstantaneously so that closure of the contact 120 is also carried outinstantaneously. Thus the staple 51 is driven into `the sheetsinstantaneously and impulsively. Thus, when sheets of papers to bestapled are inserted in the front portion of the stapler, the lever 8 ofthe changeover microswitch 7 is pressed by the sheets of paper,whereupon the contact of the microswitch departs from the pole n to comeinto contact with the pole m and, as a result, `high charging currentflows initially, as the capacitor 116 is progressively charged,itsterminal voltage is raised so that the charging current is decreasedand magnetization of the coil 122 of the electromagnet 121 is stopped indue time. In this respect, magnetizing time of the coil 122 is-ordinarily desirable to be about 100 milliseconds. This time may headjusted by changing the capacity of the capacitor 116 and the value ofthe resistor 118. When the sheets areremoved from the stapler, thecon-tact of the microswitch 7 is changed over the contact n to dischargethe charge stored in the capacitor 116 through the resistor 119. Thusthe stapling device is restored to the original state.

According to the present invention, since one of the staples is drivenby an impulsive electromagnetic force produced in an electromagnet bycausing current to flow instantaneously through the coil of theelectromagnet, the circuit of the stapler apparatus conducts only whenthe apparatus is operated so that power loss may be reduced. Moreover,when the stapler apparatus is not in operation, a discharging resistanceis connected across the capacitor to cause it to discharge rapidly sothat repeated driving of the staples may be carried out at high speedand reliably. Furthermore, in the electric stapler apparatus accordingto the invention, movement of a staple driver serves to open and close amicroswitch which is connected in series in the circuit of anelectromagnetic relay. Consequently when staples within a staplemagazine have been used up the microswitch is opened so that the staplerapparatus does not operate to drive the staples even if the sheets ofpaper are inserted into the stapler so that not only ineffectiveoperation is prevented but lack of staples may be detected. Since anarmature of the electromagnet of the stapler apparatus according to thepresent invention travels horizontally, the whole structure of thestapler apparatus is subject to lower impulsive vibration than thatencountered in the conventional apparatus in which the armature movesvertically and the stapler may be reduced in height. A guide plate isprovided for guiding pivotal movement of the bell crank which connectsthe armature of the electromagnet with a striking member for drivingstaples. Thus the bell crank pivots in contacting relation with theguide plate, and an irregular transversal swing during the pivotalmovement is avoided so that horizontal movement of the armature of theelectromagnet is transmitted effectively and uniformly to a stapledriver to drive always the staples positively.

In the staple magazine according to the present invention, a leaf springhaving a paw is secured at its end on the side wall of the staplemagazine and this paw projects inside the staple magazine through a holeformed in its side wall to engage releasably with a notch in the sidewall of a sliding case inserted in the staple magazine. A pin of a pushbutton bears against the other end of the leaf spring and the slidingcase is urged forward by a coil spring. Thus as the push button isdepressed, the paw on the leaf spring is disengaged from the notch ofthe sliding case so that the sliding case may be removed by theresiliency of the coil spring in front of the staple magazine tofacilitate replenishment of the staples. When the slide case is pressedbackward against the force of the coil spring, the paw of the leafspring engages again with the notch in the side wall of the sliding caseso that it rests easily in place within the staple magazine.

Further, according to the present invention, a changeover microswitchfor operating the stapler apparatus to drive staples into sheets ofpaper to be fastened is provided with a lever which is pressed by thesheets of paper to switch the contact of the switch to energize theelectromagnet for driving the staples. In this connection, thechangeover switch is mounted on a guide plate which is slidable axiallyand the guide plate is provided with a rack which meshes a gear wheelmounted rigidly on the end of an adjusting shaft by rotation of whichthe change-over switch moves axially along with the lever. Accordinglythe distance between the end of the sheets and the position where thesheets are tto be fastened can be adjusted by setting of the position ofthe lever of the change-over switch by properly rotating the adjustingshaft. Moreover, since the adjusting shaft is prevented from rotatingfreely by provision of a projection in the side wall of the fixture andrecesses in the retaining disc which nonrotatably accommodates theadjusting shaft so that the projection may fit releasably into one ofthe recesses in the retaining disc, the adjusting shaft does not slipout of the preset angular position by the effect of vibration so thatthe change-over switch may be positively fixed in any one of thepredetermined positions.

IFurthermore, in the electric stapler apparatus according to the presentinvention since electrical circuit elements such as capacitors,resistors and a rectifier are disposed compactly in a space behind thebase member, whole structure of the stapler apparatus can be reduced insize.

What I claim is:

1. An electric stapler apparatus comprising a base member; a fixturemounted substantially in the middle of said base member; anelectromagnet mounted on said fixture having an armature which ismovable horizontally; a substantially L-shaped staple magazine supportedon said base member having a case, adapted to receive a stick ofstaples, slidably inserted in a front opening thereof; a staple driverslidably fitted to a head portion of said L-shaped staple magazine, saidstaple driver being actuated to drive one of the staples into sheets ofpaper to be fastened together; a bell-crank supported by said staplemagazine and pivotable about the center thereof, opposite ends of saidbell-crank being connected with said armature of said electromagnet andsaid staple driver, respectively; a leaf spring having a paw and securedat one end to a side wall of said staple magazine; a notch formed in aside wall of said sliding case, said paw eX- tending through a holeformed in said side wall of said staple magazine releasably engagingwith said notch; a pin associated with a push button projecting from theside of said base member and bearing against the other end of said leafspring; a staple follower fitted slidably into said sliding case forpressing an end of said plurality of staples, a spring resilientlybearing against said staple follower; a lamp for indicating presence ofthe staples within said sliding case; a microswitch for energizing saidindicating lamp according to the position of said staple follower insaid sliding case; a guide plate mounted on a side wall of said fixturefor movement in a horizontal direction; a change-over switch mounted onsaid guide plate for energizing an electromagnetic relay, a dependinglever on said guide plate actuated by the insertion of the sheets ofpaper to be fastened, said lever actuating said changeover switch uponbeing actuated, said electromagnetic relay being arranged in the rearportion of said base member; a rack formed in said guide plate; anadjusting shaft having a gear wheel mounted on one end thereof andmeshing with said rack, said adjusting shaft being rotatably mounted insaid fixture, a locking mechanism for fixing said adjusting shaft in anyone of predetermined angular positions; an insulator plate mounted inthe rear portion of said base member, a capacitor, a charging resistor,a discharging resistor and a rectifier mounted on said insulator plate,said coil of said electromagnet being connected across terminals of apower source through a contact of said electromagnetic relay, saidelectromagnetic relay having a coil connected across said terminals ofsaid power source in series with said capacitor, said change-overswitch, said rectifier, said microswitch and said charging resistor,said `discharging capacitor resistor being connected across saidcapacitor through said change-over switch, said lamp for indicatingpresence of the staples within said sliding case being connected acrosssaid terminals of said power source; a transparent body for transmittinglight emitted by said lamp and a casing secured to said base member forcovering all of the above described components of said electric staplerapparatus.

2. An electric stapler apparatus comprising a base member; a fixturemounted substantially in the middle of said base member; anelectromagnet mounted on said fixture having an armature which ismovable horizontally; a substantially L-shaped staple magazine supportedon said base member and having a oase slidably inserted in a frontopening thereof and adapted to receive a plurality of staples; a stapledriver slidably fitted to a head portion of said L-shaped staplemagazine, said staple driver being actuated to drive one of the staplesinto sheets of paper to be fastened together; a bell-crank supported bysaid staple magazine and pivotable about the center thereof, oppositeends of said bell-crank being connected with said armature of saidelectromagnet and said staple driver respectively; a leaf spring havinga paw and secured at one end to a side wall of said staple magazine; anotch formed in a side wall of said sliding case, said paw extendingthrough a hole formed in said side wall of said staple magazine andreleasably engaging with said notch; a pin associated with a push buttonprojecting over the face of said base member and bearing against theother end of said leaf spring; a staple follower iitted slidably intosaid sliding case for pressing an end of said plurality of staples, aspring resiliently bearing against said staple follower; a microswitchadapted to be opened by means on said staple follower when sa-idplurality of staples in said case is exhausted; a guide plate mounted ona side wall of said fixture for movement in a horizontal direction; achangeover switch mounted on said guide plate for selectively energizingan electromagnetic relay; a depending lever on said guide plate movableby the insertion of the sheets of paper to be fastened to actuate saidchangeover switch; a rack formed in said guide plate; an adjusting shafthaving a gear wheel mounted on one end thereof and meshing with saidrack, said adjusting shaft being rotatably mounted in said fixture andbeing provided with a locking mechanism for lfixing said adjusting shaftin any one of a number of predetermined angular positions; an insulatorplate mounted in the rear portion of said base member, a capacitor, acharging resistor, a discharging resistor and a rectifier mounted onsaid insulator plate; and a case to cover all of said elements of saidapparatus mounted on said base member, said coil of said elec'tromagnetbeing connected across terminals of a power source through a contact ofsaid electromagnetic relay, said electromagnetic relay having a coilconnected across said terminals of said power source in series with saidcapacitor, said changeover switch, said rectifier, said microswitch andsaid charging resistor, said discharging resistor being connected acrosssaid capacitor through said changeover switch, and said electromagneticrelay being actuated instantaneously by the charging current of saidcapacitor to make said electromagnetic coil instantaneously conduct toproduce impulsive electromagnetic force to drive the staples into thesheets of paper to be fastened.

References Sited by the Examiner UNITED STATES PATENTS 2,205,861 6/ 1940VOussani 1-409 XR 2,403,947 7/1946 Oussani 1-409 XR 2,545,397 3/1951Wampler 1 417 XR 2,643,307 6/1953 Geel 1-409 XR 2,656,537 10/1953 Geel1-409 2,719,528 10/ 1955 Gabrielsen 221-6 XR 2,801,414 8/1957 vMueller1-415 XR 2,910,700 11/1959 De Paolo 1-409 XR 2,957,174 10/1960 Oussani1-409 3,080,036 3/19613 Robbins et al. 221-6 XR 3,141,171 7/1964 Doyleet al. 1-44.6

GRANVILLE Y. CUSTER, JR., Primary Examiner.

1. AN ELECTRIC STAPLE APPARATUS COMPRISING A BASE MEMBER; A FIXTUREMOUNTED SUBSTANTIALLY IN THE MIDDLE OF SAID BASE MEMBER; ANELECTROMAGNET MOUNTED ON SAID FIXTURE HAVING AN ARMATURE WHICH ISMOVABLE HORIZONTALLY; A SUBSTANTIALLY L-SHAPED STAPLE MAGAZINE SUPPORTEDON STICK BASE MEMBER HAVING A CASE, ADAPTED TO RECEIVE A STICK OFSTAPLES, SLIDABLY INSERTED IN A FRONT OPENING THEREOF; A STAPLE DRIVESLIDABLY FITTED TO A HEAD PORTION OF SAID L-SHAPED STAPLE MAGAZINE, SAIDSTAPLE DRIVER BEING ACTUATED TO DRIVE ONE OF THE STAPLES INTO SHEETS OFPAPER TO BE FASTENED TOGETHER; A BELL-CRANK SUPPORTED BY SAID STAPLEMAGAZINE AND PIVOTABLE ABOUT THE CENTER THEREOF, OPPOSITE ENDS OF SAIDBELL-CRANK BEING CONNECTED WITH SAID ARMATURE OF SAID ELECTROMAGNET ANDSAID STAPLE DRIVER, RESPECTIVELY; A LEAF SPRING HAVING A PAW AND SECUREDAT ON END TO A SIDE WALL OF SAID STAPLE MAGAZINE; A NOTCH FORMED IN ASIDE WALL OF SAID SLIDING CASE, SAID PAW EXTENDING THROUGH A HOLE FORMEDIN SAID SIDE WALL OF SAID STAPLE MAGAZINE RELEASABLY ENGAGING WITH SAIDNOTCH; A PIN ASSOCIATED WITH A PUSH BUTTON PROJECTING FROM THE SIDE OFSAID BASE MEMBER AND BEARING AGAINST THE OTHER END OF SAID LEAF SPRING;A STAPLE FOLLOWER FITTED SLIDABLY INTO SAID SLIDING CASE FOR PRESSING ENEND OF SAID PLURALITY OF STAPLE, A SPRING RESILIENTLY BEARING AGAINSTSAID STAPLE FOLLOWER; A LAMP FOR INDICATING PRESENCE OF THE STAPLESWITHIN SAID SLIDING CASE; A MICROSWITCH FOR ENERGIZING SAID INDICATINGLAMP ACCORDING TO THE POSITION OF SAID STAPLE FOLLOWER IN SAID SLIDINGCASE; A GUIDE PLATE MOUNTED ON A SIDE WALL OF SAID FIXTURE FOR MOVEMENTIN HORIZONTALY DIRECTION; A CHANGE-OVER SWITCH MOUNTED ON SAID GUIDEPLATE FOR ENERGING AN ELECTROMAGNETIC RELAY, A DEPENDING LEVER ON SAIDGUIDE PLATE ACTUATED BY THE INSERTION OF THE SHEETS OF PAPER TO BEFASTENED, SAID LEVER ACTUATING SAID CHANGEOVER SWITCH UPON BEINGACTUATED, SAID ELECTROMAGNETIC RELAY BEING ARRANGED IN THE REAR PORTIONOF SAID BASE MEMBER; A RACK FORMED IN SAID GUIDE PLATE; AN ADJUSTINGSHAFT HAVING A GEAR WHEEL MOUNTED ON ONE END THEREOF AND MESHING WITHSAID RACK, SAID ADDJUSTING SHAFT BEING ROTATABLY MOUNTED IN SAIDFIXTURE, A LOCKING MECHANISM FOR FIXING SAID ADJUSTING SHAFT IN ANY ONEOF PREDETERMINED ANGULAR POSITIONS; AN INSULATOR PALTE MOUNTED IN THEREAR PORTION OF SAID BASE MEMBER, A CAPACITOR, A CHARGING RESISTOR, ADISCHARGING RESISTOR AND A RECTIFIER MOUNTED ON SAID INSULATOR PLATE,SAID COIL OF SAID ELECTROMAGNET BEING CONNECTED ACROSS TERMINALS OF APOWER SOURCE THROUGH A CONTACT OF SAID ELECTROMAGNETIC RELAY, SAIDELECTROMAGNET RELAY HAVING A COIL CONNECTED ACROSS SAID TERMINALS OFSAID POWER SOURCE IN SERIES WITH SAID CAPACITOR, SAID CHANGE-OVERSWITCH, SAID RECTIFIER, SAID MICROSWITCH AND SAID CHARGING RESISTOR,SAID DISCHARGING CAPACITOR RESISTOR BEING CONNECTED ACROSS SAIDCAPACITOR THROUGH SAID CHANGE-OVER SWITCH, SAID LAMP FOR INDICATINGPRESENCE OF THE STAPLES WITHIN SAID SLIDING CASE BEING CONNECTED ACROSSSAID TERMINALS OF SAID POWER SOURCE; A TRANSPARENT BODY FOR TRANSMITTINGLIGHT EMITTED BY SAID LAMP AND CASING SECURED TO SAID BASE MEMBER FORCOVERING ALL OF THE ABOVE DESCRIBED COMPONENTS OF SAID ELECTRIC STAPLERAPPARATUS.